async-func-dstr-const-async-ary-ptrn-elem-id-init-skipped.js (2297B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-binding-for-await/ary-ptrn-elem-id-init-skipped.case 4 // - src/dstr-binding-for-await/default/for-await-of-async-func-const-async.template 5 /*--- 6 description: Destructuring initializer is not evaluated when value is not `undefined` (for-await-of statement) 7 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 8 features: [destructuring-binding, async-iteration] 9 flags: [generated, async] 10 info: | 11 IterationStatement : 12 for await ( ForDeclaration of AssignmentExpression ) Statement 13 14 [...] 15 2. Return ? ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult, 16 lexicalBinding, labelSet, async). 17 18 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 19 20 [...] 21 4. Let destructuring be IsDestructuring of lhs. 22 [...] 23 6. Repeat 24 [...] 25 j. If destructuring is false, then 26 [...] 27 k. Else 28 i. If lhsKind is assignment, then 29 [...] 30 ii. Else if lhsKind is varBinding, then 31 [...] 32 iii. Else, 33 1. Assert: lhsKind is lexicalBinding. 34 2. Assert: lhs is a ForDeclaration. 35 3. Let status be the result of performing BindingInitialization 36 for lhs passing nextValue and iterationEnv as arguments. 37 [...] 38 39 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 40 41 SingleNameBinding : BindingIdentifier Initializer_opt 42 43 [...] 44 6. If Initializer is present and v is undefined, then 45 [...] 46 7. If environment is undefined, return PutValue(lhs, v). 47 7. Return InitializeReferencedBinding(lhs, v). 48 ---*/ 49 var initCount = 0; 50 function counter() { 51 initCount += 1; 52 } 53 54 var iterCount = 0; 55 var asyncIter = (async function*() { 56 yield* [[null, 0, false, '']]; 57 })(); 58 59 async function fn() { 60 for await (const [w = counter(), x = counter(), y = counter(), z = counter()] of asyncIter) { 61 assert.sameValue(w, null); 62 assert.sameValue(x, 0); 63 assert.sameValue(y, false); 64 assert.sameValue(z, ''); 65 assert.sameValue(initCount, 0); 66 67 iterCount += 1; 68 } 69 } 70 71 fn() 72 .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) 73 .then($DONE, $DONE);